The unheard conversation between your gut microbiome and the environment directly translates to how you store fat, says a team of researchers from the UT Southwestern Medical Center. Their new research, novel in its exactness to determine the processes of gut bacteria, provides clues to how our body’s circadian clock and digestive microflora interact with each other to influence body fat accumulation. These findings further implicate the gravity of choice in weight gain and loss among individuals. While genetics may predispose a person to have certain types of bacteria, environmental factors (entirely within one’s control) play a stronger role in how lean or overweight one is in adult life.

“There is accumulating evidence that certain bacteria that live in our gut predispose us to gain weight, especially when we consume a high-fat, high-sugar ‘Western-style’ diet,” explained lead author Yuhao Wang. He noted that intestinal microbiota, which regulates body composition, establishes a link with one’s own circadian clock to determine just how much lipids the body should store. In essence, the body is constantly adapting to change in ways it deems to be crucial for survival.

Wang, along with his colleague, Dr. Lora Hooper, observed several mice with difference microbiome profiles. Those that lacked a certain transcription factor called NFIL3 were able to maintain their weight better than mice who had the bacteria. Expanding their research more, Wang saw that circadian rhythms “talked” to the gut microbiome, determining whether NFIL3 was produced or not.

The researchers used the verb “talk” for lack of a better word, but perhaps a more appropriate term would be “hack” — for the way the body assumed what is day/night affected the robustness of how the genes drove lipid uptake. Mice models that lacked NFIL3 were able to maintain a healthy weight even on a high-fat diet.

What affected these levels was the body’s circadian clock. This is our own internal system that senses the cycles of day and night and which turn on and off the metabolism as needed. Gut microbiomes, even if they are not directly exposed to light, are able to discern light cues from the visual and nervous system to regulate gene expression.

“So what you have is a really fascinating system where two signals from the environment come in — the microbiome and the day-night changes in light — and converge on the gut lining to regulate how much lipid you take up from your diet and store as fat,” said Dr. Hooper. “It could also help to explain why people who work the night shift or travel abroad frequently — which disrupts their circadian clocks — have higher rates of metabolic diseases such as obesity, diabetes, and cardiovascular disease.”

Weighing in on the obesity crisis

For the most part, obesity is self-inflicted. There are those who do have a genetic disorder or medical condition which contributes to excessive weight gain, but medical doctors have noted that bad eating habits along with a sedentary lifestyle are two of the biggest reasons why people are overweight or obese.

Numerous studies have additionally concluded that gut bacteria could affect the way you think. Those with mood disorders such as depression and anxiety are usually recommended by wellness doctors to begin taking in more magnesium and B vitamins which improve one’s nutritional profile.